Yarn assembly apparatus for false twisting yarn



J n- 2 969 E. J. BERGER, JR.. ETAL 3,422,613

YARN ASSEMBLY APPARATUS FOR FALSE T WISTING YARN Shet Filed May 8, 1967 INVEN'TORS. EMIL J. BERGER, JR. WILLIAM KIRK WYATT W+W ATTORNEYS.

YARN ASSEMBLY APPARATUS FOR FALSE TWISTING YARN Filed May 8, 1967 Sheet INVENTORS. EMIL J. BERGER, JR. WILLlAM KIRK WYATT ATTORNEYS.

21, 1969' E. J. BERGER, JR. ETAL 3,422,613

YARN ASSEMBLY APPARATUS FOR FALSE TWISTING YARN e T m P s a M d INVENTORS.

EMIL J. BERGER,JR. WILLIAM KIRK WYATT WMBJ Fig. 6

I BY

ATTOR N EYS J n- 2 1969 a. J. BERGER, JR.. ETAL 3,422,613

I YARN ASSEMBLY APPARATUS FOR FALSE TWISTING YARN Filed May 8, 1967 Sheet 4 I HEATER [N VEN 'TORS. EMIL J. BERGER, JR. WILLIAM KIRK WYATT ATTORNEYS.

United States Patent 3,422,613 YARN ASSEMBLY APPARATUS FOR FALSE TWISTING YARN Emil .I. Berger, Jr., Wayne, and William Kirk Wyatt,

Lansdale, Pa., assignors to Turbo Machine Company,

Lansdale, Pa., a corporation of Pennsylvania Filed May 8, 1967, Ser. No. 636,976

US. CI. 57-34 12 Claims Int. Cl. D01h 13/26; D02g 3/02 ABSTRACT OF THE DISCLOSURE A texturing method and apparatus is disclosed in which two ends of untwisted multi-filament heat-settable yarns are false-twisted together, heat-set, cooled and separated to provide two ends of textured yarn. The method and apparatus disclosed achieves the transition of two ends of untwisted multi-filament yarn into a two-ply helically twisted yarn smoothly and progressively in a series of stages. A very small degree of twist is introduced at the first stage. Thus, the angle of first departure of the untwisted filaments from the substantially linear path is small. The number of turns of twist per inch introduced at the second and succeeding stages is progressively greater until the full transition from the untwisted to the twisted condition is attained. In the preferred method and apparatus, the untwisted single ends of yarn are preheated prior to twisting.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to texturing heat-settable multifilament yarns by false-twisting techniques.

Description of the prior art Prior art patents include British Patent 901,922 and US. Patents 2,807,130, 2,987,869, 3,154,906, 3,091,908, 3,192,697, 3,237,391, and 3,237,392.

Summary of the invention The present invention is characterized by the smooth progressive manner in which two ends of untwisted multifilament yarns are twisted together into a two-ply twisted yarn. The transition from untwisted substantially parallel filaments to the two-ply twisted condition is accomplished in a plurality of stages or steps, The assembly device is such that but a few turns of twist per inch are introduced at the first stage, a somewhat greater number of turns of twist per inch are introduced at the second stage, and so on until the final stage at which the full number of turns of twist per inch are introduced. Due to the gradual transition from untwisted to fully twisted condition, the initial angle of departure of the filaments from the linear direction of the yarn path is small, and this has the advantage of avoiding the entanglements, snags and other irregularities which are produced when the yarn filaments are transformed too rapidly from untwisted to twisted condition.

The assembly of untwisted multi-filament yarns into the two-ply fully-twisted form is accomplished by a device which inhibits or restrains the twist from running back upstream. This device may be viewed, looking downstream from the untwisted yarn source, as an assembly device, or, it may be viewed, looking upstream from the yarnend separation device, as a twist-barrier or inhibitor. When the device is viewed as a barrier or inhibitor looking upstream, the yarn in the first stage of the twist inhibitor will have less turns of twist per inch than the yarn downstream therefrom. And, in the next succeeding upstream stages of the twist-inhibitor device, the number of turns of twist per inch will become less and less until at the upstream end of the twist-barrier device the yarn ends are substantially free of twist.

By using twist-barrier or restraint devices of the multistage type described herein, the texturing apparatus may be run at considerably higher speeds since the untwisted single ends of yarn are assembled and twisted smoothly and progressively, and without abrupt change in direction, thereby avoiding the entanglements which tend to develop when the transition from untwisted to twisted condition is made too suddenly.

The present application discloses several dilferent forms of multi-stage assembly or twist-barrier devices. Each is effective to restrain, in a plurality of stages, the passage of the twist upstream, whereby, as viewed looking downstream, the transition of the filaments from untwisted parallel condition to the twisted two-ply condition is made smoothly and progressively.

Brief description of the drawing FIG. 1 is a diagrammatic illustration of a texturizing system incorporating one form of multi-stage twist-barrier device in accordance with the present invention;

FIG. 2 is an enlarged fragmentary plan view of the crossed rollers of the twist-barrier device, looking down along the line II-II of FIG. 1;

FIG. 3 is a fragmentary view, in front elevation, looking along the line IIIIII of FIG. 2. It should be noted that the rollers are actually circular in cross section, and that the oval cross sections appearing in FIG. 3 are due to the fact that the line of view IIIIII is not per-pendicular to the axis of either of the rollers.

FIG. 4 is a fragmentary view, in side elevation, looking along the line IVIV of FIG. 2;

FIG. 5 is a front view of an alternate form of multi stage twist-barrier device;

FIG. 6 is a side view of the device of FIG. 5;

FIG. 7 is a diagrammatic perspective illustration of yet another form of multi-stage twist-barrier device.

Description of the preferred embodiments In FIG. 1, two ends 12 and 13 of multi-filament untwisted heat-settable yarns are pulled through the texturizing or false-twist apparatus by two pairs of delivery rolls and 66 and delivered through reciprocating traversing means 71 and 72 to the take-up rolls 73 and 74.

In FIG. 1, the path of the two ends of yarn 12 and 13 may be traced from the supply packages 10 and 11 down through the pretwister device 14, under and around the guide rollers 15, up through the guide eye 16, around the tension-adjusting device 17, over the guide roller 19, down through the left groove 31 of the arcuate heater 30, through the multi-stage twist-barrier or restraining device B, up (as a two-ply twisted yarn 18) through the right groove 32 of the heater 30, over and about the cornering and guide rollers 42, 43 and 44, down to the separation device S, and then (as the separate ends 12 and 13 of textured yarn) to the delivery rolls 65 and 66, and to the take-up rolls 73 and 74.

In the region between the supply packages 10 and 11 and the upstream side of the twist-barrier device B, the yarn ends 12 and 13 are untwisted and the filaments thereof lie substantially flat and parallel. It is in this form that the yarn ends 12 and 13 first pass through the arcuate contact heater 30. The concept of so doing and the nonobvious advantages to be derived therefrom are described in the copending application Ser. No. 636,814, filed May 8, 1967, of Emil I. Berger, Jr., entitled Preheating in Yarn Texturing, filed concurrently with the present application and assigned to the same assignee.

Between the downstream side of the twist-barrier device B and the separation device S, the two ends of yarn 12 3 and 13 are twisted together forming the two-ply yarn which has been designated 18. At the separation device S, the two plies are separated and passed separately to the take-up rolls 73 and 74.

As has already been indicated, the novelty of the present invention is directed primarily to the manner in which the untwisted filaments of the two ends of yarn are smoothly and progressively transformed into tightly twisted condition. This end result is attained by a multistage twist-barrier or inhibitor device B which progressively inhibits run back of the twist. Several forms of device B are disclosed in the present application. One form is that of a pair of crossed rollers, this form being shown in FIGS. 1, 2, 3 and 4. An alternate form of multi-stage twist-barrier device is shown in FIGS. 5 and 6, and yet another form is shown in FIG. 7.

Each of the several forms of multi-stage twist-barrier device shown and described in the present application achieves a smooth and progressive transition from untwisted to tightly twisted condition, as viewed looking downstream. Because of the smooth and progressive manner in which the untwisted parallel filaments are transformed into a tight helical twist having an angle of say 45, the entanglements or snags that tend to develop when yarns are twisted together abruptly are avoided. As a result, the stresses that tend to cause yarn breakage are eliminated. The resultant two-ply twisted yarn which passes through the texturizing zone is tightly bundled, comprising closely adherent filaments with substantially few, if any, stray filaments. As a result, the texturizing apparatus can be operated at higher speeds without encountering the yarn stresses and resultant breakages which would otherwise tend to occur. Thus, a superior textured yarn is produced.

As has already been indicated, the device B may be viewed in two aspects. It may be viewed as a twist-barrier device which inhibits or restrains the running back upstream of the twist of the two-ply twisted yarn which ex tends from the separation point S to the device B. It may also be viewed as a yarn filament assembly device in which the untwisted parallel filaments of the two yarn ends 12 and 13, which approach the device B in the downstream direction, are assembled into the two-ply tightly twisted yarn 18.

It will be convenient to consider first the aspect of the device B as a twist-barrier device which operates to inhibit the passage of the twist of the two-ply yarn 18 into the region which lies upstream from the device B.

In FIGS. 1-4, the device B comprises a pair of laterally-disposed vertically-separated crossed rollers 81 and 82 each mounted for free rotation in bracket 89. The angle at which the rollers cross is not critical. In the illustration they are shown 90 apart. The yarn ends 12 and 13 are pulled downwardly through crotch 83 of the crossed rollers and upwardly through the opposite crotch 84, the crotches restraining lateral movement of the yarn along the rollers. Due to the frictional engagement of the rollers by the yarn ends 12 and 13 as they are pulled through the crotches 83, 84 in the direction indicated by the arrows P, the upper roller 81 and the lower roller 82 are rotated in the directions indicated in FIGS. 24 by the arrows R.

It will be understood that as a result of the rotational forces imparted to the yarns when the two ends 12 and 13 are pulled apart at the separation device S, the twoply twisted yarn 18 rotates about its linear yarn path as the twist runs back upstream from the separation device S. In the illustration, the two-ply yarn 18 is assumed to have an S twist, and the direction of rotation of the two-ply yarn is indicated by the arrows T.

Considering the crossed rollers 81 and 82 of FIGS. 14 as a device for restraining the passage of twist upstream, and looking upstream at the device, it will be noted that the point of first contact of the twist is at a point 184 on the downstream side of the upper roller 81. At this point 184, a component of the helical movement M of the yarn filaments is parallel to the axis of rotation of the roller 81, and, as a result thereof, the surface of the roller 81 imparts a resistive component of force to the yarn which tends to inhibit the helical rotation thereof. As a result, the number of turns of twist per inch upstream from the point 184 is less. This is indicated in FIGS. 3 and 4. At a point on the downstream side of the lower roller 82, the two-ply yarn 18 of lessened twist makes a further contact with the rollers, and this contact is maintained until the yarn leaves the lower roller 82 at point 186 on the upstream side thereof. Here again, a component of the helical movement of the yarn filaments is parallel to the axis of rotation of the roller 82 and a component of resistive force is imparted to the yarn by the roller surface which tends to inhibit the helical rotation of the yarn. As a consequence, a progressive lessening occurs in the number of turns of twist per inch in the region between points 185 and 186. As the now substantially lessened twist tries to run upstream, it encounters the upstream side of the upper roller 81 at point 187, and here again a component of the helical movement of the yarn is axial to the upper roller 81. As a result, further resistance is introduced by the roller surface to the helical movement of the yarn, and, as a consequence, there is substantially zero twist upstream of point 187.

In summary then the crossed rollers 81, 82, inhibit or restrain the twist of the two-ply twisted yarn 18 from running back upstream. The restraint is imposed in steps, establishing stages of lessened twist. A first stage extends from point 184 at the downstream side of the upper roller 81 to point 185 at the downstream side of the lower roller 82. A second stage extends from point 185 to point 186 on the upstream side of the lower roller 82. A third stage extends from point 186 to point 187 on the upstream side of the upper roller 81.

Viewing the crossed rollers 81-82 downstream as an assembly device, it will be seen that the untwisted substantially parallel filaments of the yarn ends 12 and 13 are gradually and progressively transformed into a twoply tight twist having an angle on the downstream side of the device of the order of 45. But the angle of first departure of the untwisted filaments from the direction of the linear path is small, and is thereafter gradually and progressively increased. This technique produces a two-ply twisted yarn in which each ply comprises tightly bundled closely adherent filaments with few, if any, stray filaments. The filaments of one ply do not become entangled or intermeshed with filaments of the other ply, and when the two plies are separated at the separation device S, the separation is clean and without cross stresses. The tension on the two plies remains substantially equal, and the separation point remains relatively fixed. Thus, at least in some installations, it will no longer be necessary to provide guide means 63 and 64 which, while remaining at fixed spacing relative to each other, move laterally back and forth in response to changes in tension of one ply relative to the other, to change the positions of the separated plies relative to the pairs of conical rollers 65 and 66. A separation device of the type just referred to is shown and described in the patent application of William Kirk Wyatt, entitled Yarn Separating Means, filed June 17, 1965, Ser. No. 464,797, assigned to the assignee of the present application. While guide means which move in response to changes in tension may no longer be required, the employment of pairs of conical rolls, such as 65 and 66, may still be desirable in that by adjustment of the spacing between the guide means 63 and 64 the speed at which the yarn is pulled through the apparatus is adjustable. But Where such adiustment is not deemed to be necessary, it is contemplated that the multi-stage twistbarrier means described herein will make it possible, at least in certain installations, to employ cylindrical rather than conical delivery rolls.

In FIGS. 14, the two-ply twisted yarn 18 is illustrated as having a right hand or S twist. When the yarn to be texturiz'ed is to be given a left hand or Z twist, the crossedroller device is rotated 90 (in either direction) from that shown in FIGS. 1-4 and the yarn is pulled through the opposing crotches 85 and 86 of the crossed rollers 81-82. This 90 shift in the positions of the crossed rollers 81 and 82 is necessary in order that a component of Z helical movement of the yarn filaments be parallel to the axis of the under roller 82, and not circumferential thereto as would be the case if the 90 shift were not made. When yarn is pulled about a rotatable roller in such manner that the helical path is circumferential relative to the surface of the roller, no resistance is imposed upon the yarn to restrain the helical rotation of the twist, and the twist is permitted to pass rather than to be inhibited.

An alternate form of multi-stage twist-barrier device is shown in FIGS. 5 and 6. In FIGS. 5 and 6, a large diameter pin 94 and a smaller diameter pin 95 are mounted on an adjustable bracket 90 below the lower end of heater 30 in such positions that the pins 94 and 95 are in alignment with the axis of the heater 30. Pin 94 has an annular groove of such diameter that opposite sides of the groove, identified as 194 and 294, are in alignment with the grooves 31 and 32 of the heater 30. The smaller pin 95, located below pin 94 is mounted in a slot 96 and its position is vertically adjustable, thereby to adjust the angle of the yarn path between point 194 and the pin 95, and also the angle between point 294 and the pin 95.

The yarn is threaded in the manner shown in FIG. 5. The untwisted substantially flat parallel multi-filament ends 12 and 13 from heater groove 31 contact the groove of pin 94 at point 294 at the upstream side, then pass under and around the pin 95, then contact the groove of pin 95 at point 194 on the downstream side, and then pass up and into the heater groove 32.

In operation, viewing the device of FIGS. 5-6 from the downstream side, as the twist of the rolling two-ply twisted yarn 18 tries to move upstream, resistance to its helical rotation is first encountered at point 194, and as a result the number of turns of twist per inch in the region below point 194 is lessened. An additional component of resistance is imparted to the helically twisting yarn by the pin 95 and, accordingly, in the region between the under surface of the pin 95 and the point 294 an the upstream side of pin 94 a further decrease occurs in the number of turns of twist per inch. A still further point of resistance is at point 294. At this point, the final bit of twist is removed, and upstream of pin 94 the two yarn ends 12 and 13 are untwisted and the filaments lie substantially fiat and parallel in the heater groove 31.

FIGURE 7 illustrates yet another form of multistage twist-barrier device. In FIGURE 7, when the twist of the two-ply twisted yarn 18 tries to run back upstream, it encounters first the pin 101, then the pin 102, then the guide 106, then the tension adjusting device 107, and finally the guide 108. Pins 101 and 102 are mounted on the enlarged head 103 of a stud 109 having a threaded stem 104 which carries a wing nut 105. The pins 101 and 102 are equi-distant from the axial center of the stud 109 so that rotation of stud 109 adjusts the positions of the pins 101-102 relative to the yarn path. In the drawing, adjustment of stud 109 counterclockwise will increase the angle of departure of the two-ply yarn 18 from the linear path of the yarn downstream from pin 101. The greater the angle at pin 101, the greater the resistance offered to the passage of the twist as it tries to run upstream, and the larger the decrease in the number of turns per inch of the yarn in the region between the pins 101 and 102. Pin 102 introduces further resistance to the twist, so that upstream of the pin 102, the yarn twist is further reduced. At the guide means 106 still further resistance to passage of twist is encountered. The resistance at 106 is considerable, due to the angle of bend of the yarn path at this point, and due to the fact that guide 106 is not a rolling surface. Thus, the twist upstream from the guide 106 is very much reduced. A further reduction in the number of turns per inch occurs as the yarn passes over the tension wheel 107, and at the final guide pin 108 substantially all of the twist is eliminated so that the ends 12 and 13 thereabove are substantially without twist.

If the twist-barrier or twist-restraining device illustrated in FIG. 7, be now considered as a yarn assembly device, it will be seen that the two ends 12 and 13 of untwisted multi-filament substantially parallel incoming yarns are first given a very slight degree of twist between the guide 108 and the tensioning device 107, then a very slight increase in twist between the tensioning device 107 and the guide 106, then a substantial increase in the degree of twist between the guide 106 and the pin 102, a further increase in twist between the pin 102 and the pin 101, and a final degree of twist downstream from the pin 101.

It will be seen that the present invention provides means for assembling two ends of multi-filament yarn into a two-ply yarn in a way that avoids entanglement or intermeshing of the filaments of one ply with those of the other. The assembly devices take the yarns parallel to each other and then gradually permit the filaments to twist while under tension. As a result, each ply is a tightly bundled unit with substantially no stray filaments. The initial slight degree of twist is then increased in steps until the final degree of twist is attained.

While the multi-st-age assembly technique may be employed without preheating the untwisted parallel filaments, the use of a preheater for the untwisted filaments in combination with the multi-stage assembly technique herein described allows the texturing apparatus to be run at speeds very considerably higher than has been permissible theretofore using prior art apparatus and methods. The use of the preheater is particularly advantageous where the yarn. denier is relatively large, for example, 70 denier for each end. In such cases, a fifty per cent increase has been realized in the speed 'at which the yarn ends are through the texturing apparatus.

In some cases, it may be desirable to insert a known form of tension control device in the path of the untwisted yarn ends between the heater groove 31 and the assembly device B. Such a device is indicated in the drawing by the dot-and-dash rectangle 120. By means of the tension-control device 120, the tension on the untwisted heated filaments in groove 31 may be made relatively low, while keeping a considerable amount of tension on the twisted yarns downstream thereof.

While the preferred embodiments of this invention have been described in some detail, it will be obvious to one skilled in the art that various modifications may be made without departing from the invention as hereinafter claimed.

What is claimed is:

1. In a texturing machine (a) a source of two ends of multi-filament yarn, the ends being pretwisted at start-up to form a two-ply yarn having a preselected number of turns of twist per inch,

(b) delivery means for pulling said yarn ends,

(c) separation means upstream from said delivery means for separating the two-ply yarn into single ends,

((1) multi-stage twist-restraining means upstream from said separating means for applying to said two-ply yarn at spaced intervals twist-restraining resistance to decrease in steps in the upstream direction the degree of twist from a full twist to substantially zero twist,

(e) the magnitude of the resistance applied at the several points being such that only a slight degree of twist remains in the first stage downstream from the substantially zero twist region.

2. Apparatus according to claim 1 characterized in that the twist-restraining means comprises freely rotatable first and second crossed rollers mounted on skewed axes form ing oppositely disposed crotches, and in that the yarn is pulled through one crotch, then about the second roller, and then through the opposing crotch, and in that said resistance is applied at the downstream side of said first roller, at said second roller, and at the upstream side of said first roller.

3. Apparatus according to claim 1 characterized in that the twist-restraining means comprises a pair of crossed rollers mounted for free rotation one above the other and angularly disposed relative to each other forming opposing crotches, and in that the yarn is pulled dOWn through one crotch, then under the lower roller, and then up through the other crotch, and in that said resistance is applied at the downstream side of the upper roller, at the under side of said lower roller, and at the upstream side of said upper roller.

4. Apparatus according to claim 1 characterized in that the twist-restraining means comprises a larger diameter pin and a smaller diameter pin mounted in alignment, and in that the yarn is pulled along one side of said larger pin, about the smaller pin, and then along the opposite side of the larger pin, and in that said resistance is applied at the downstream side of said larger pin, at the smaller pin, and at the upstream side of the larger pin.

5. Apparatus according to claim 1 characterized in that the twist-restraining means comprises in order in the upstream direction, a pair of adjustable pins disposed at an adjustable angle relative to the yarn path and between which the two-ply twisted yarn is pulled, guide means upstream thereof, and a yarn-tension device, said guide means being so disposed between said yarn-tension device and said pair of adjustable pins that the yarn changes direction substantially as it is pulled through said guide means.

6. In a method of texturing yarn,

(a) providing two ends of multi-filament yarn, the ends of which are pretwisted at start-up to form a two-ply yarn having a selected number of turns of twist per inch,

(b) pulling the yarn,

(c) at a point upstream from the pulling point separating the two-ply yarn into single ends,

(d) at a point upstream from said separating point taking the two ends of untwisted substantially fiat parallel multi-filament yarns and applying a slight degree of twist thereto to form a lightly twisted two-ply yarn and then at succeeding downstream points increasing progressively the degree of twist until the final degree of twist is obtained.

7. Apparatus according to claim 1 characterized in that heater means are provided upstream from said twistrestraining means for heating the substantially zero twist yarns.

8. Apparatus according to claim 7 characterized in that heater means are also provided downstream from said twist-restraining means.

9. The method according to claim 6 characterized in that the two ends of untwisted yarns are heated prior to applying the slight degree of twist.

10. The method according to claim 9 characterized in that the yarn having the final degree of twist is also heated.

11. In a yarn texturing method in which a two-ply multi-filament twisted yarn is separated and the twist tends to run upstream, the improvement which comprises the steps of imposing, at a first point on the yarn upstream from the separation point, a resistance opposing helical rotation of the twist to impose a partial restraint to the upstream movement of the twist, thereby to lessen the degree of twist upstream from said first point, and then at one or more additional points upstream from said first point imposing further resistance to impose further restraint to further lessen the degree of twist to substantially zero.

12. The method according to claim 9 characterized in that the two ends of untwisted yarns which are heated prior to the application of the slight degree of twist are under relatively low tension and in that the tension is increased before twisting begins.

References Cited UNITED STATES PATENTS 2,788,634 4/1957 Crouzet 57106 2,890,568 6/1959 Willens 57--34 XR 2,987,869 6/1961 Klein 5734 3,192,697 7/1965 Carruthers 5734 3,270,492 9/1966 Fitton et al 5734 XR 3,289,400 12/1966 Scragg 5734 3,321,904 5/1967 Horvath et al. 5734 XR 3,355,872 12/1967 Gilcrist et al 5734 XR FOREIGN PATENTS 991,899 5/1965 Great Britain.

LEONARD D. CHRISTIAN, Primary Examiner.

D. E. WATKINS, Assistant Examiner.

US. Cl. X.R. 57157 

